In recent years, from the viewpoint of energy and maintenance savings, a variety of lighting apparatuses that use a small and lightweight LED that has a high output and a long life span as a light source have been developed.
The aforementioned lighting apparatus is suitable for use as a road lighting or the like. The lighting apparatus has a light source apparatus that includes a plurality of mounts attached to an apparatus main body and a plurality of LED modules attached to the mounts. The light source apparatus is covered by a cover glass attached to the apparatus main body.
An LED that is used as a light source for illumination is a high power diode, and a large quantity of heat is generated by each LED. If the generated heat accumulates in the vicinity of the LED, the heat leads to a decrease in the optical output of the LED or a deterioration in the life span characteristics thereof or the like.
According to the optical unit, since a light source apparatus that is equipped with a plurality of LEDs is arranged inside an enclosed space on which a cover glass is provided in the apparatus main body, the generated heat by the plurality of LEDs is liable to be confined within the enclosed space.
Consequently, there is the problem that the heat dissipation properties of each LED are low, and this situation is liable to lead to a decrease in the optical output of the LEDs and a deterioration in the life span characteristics thereof. Further, since a plurality of LED modules are directly attached to a mount that is fixed to the apparatus main body, if, for example, a malfunction occurs in one part of an LED module, it is not possible to replace only the LED module in which the malfunction occurs, and the entire lighting apparatus must be replaced. Hence, there is also the problem that the configuration leads to an increase in maintenance costs.